1. Field of the Invention
The invention relates to devices for removing solid deposits in tanks and vessels and for preventing formations of solid deposits on the bottom of the tanks. In particular, the invention is related to devices for removing solid deposits in crude oil storage tanks and preventing formations of solid deposits on the bottom of the tanks.
2. Description of the Related Art
Devices for cleaning tanks or vessels and/or for preventing deposits from forming on the bottom of the tanks or vessels are known in the art. Exemplary of such devices are the following U.S. Patents:
U.S. Pat. No. 4,913,819 discloses a liquid jet solids removal system for process vessels for removing solids such as sand and sediment which accumulate along the bottom wall of the vessel during operation. A plurality of elongated manifolds are arranged to extend longitudinally along the vessel bottom wall and each manifold is provided with an array of jet nozzles which are arranged along the manifold bottom side and top side, respectively. The nozzles extend in a direction such as to create a substantially vortical flow of liquid to entrain and urge the fluidized solids mixture toward the solid removal outlet opening in the vessel. The manifolds are supported in a standoff position from the vessel bottom wall by adjustable support brackets and a generally arcuate shield is supported above and spaced from each of the jet manifolds to redirect the liquid flow out of the nozzles to enhance the vertical flow pattern.
U.S. Pat. No. 4,244,523 discloses an apparatus for cleaning tanks or vessels, such as automotive and railway tank cars. A tiltable frame having a wash nozzle assembly pivotedly mounted thereon is pivotedly mounted above a fixed support frame. The tiltable frame has, fixedly mounted thereon, an air motor which is operatively connected to a second gear box. The first gear box is operatively connected to the wash nozzle assembly to move the assembly back and forth along the longitudinal axis of the tank or vessel to be cleaned. The second gear box is operatively connected to the fixed support frame to tilt the tiltable frame and thereby move the wash nozzle in both directions along the latitudinal axis of the tank of vessel to be cleaned.
U.S. Pat. No. 3,985,572 discloses an automatic spray cleaning apparatus and method for rapidly and efficiently removing material coated on the surface of an object. In accordance with the invention the axis of the cleaning liquid spray forms an acute angle with the object surface and such angle, as well as the distance along such axis between the spray nozzle and the object surface, are both maintained substantially constant over a given surface area. In addition, the pressure of the cleaning liquid at the surface of of the object is also maintained substantially constant over such given area. The spray nozzles are automatically moved rotationally about a cleaning axis and longitudinally along such axis to scan over the object surface along a predetermined path while maintaining the spacing distance and angle substantially constant during rotation of the nozzles about the cleaning axis at a given longitudinal position on such axis, by a motor operated drive which may be controlled by an electronic computer. The cleaning apparatus is especially useful for cleaning the interior surface of container tanks, such as chemical reactor tanks which contain internal baffles and other obstructions. The nozzles are mounted on folding support arms which are supported on a vertical shaft to fold such arms in and out relative to the axis of such shaft. In addition, the support shaft rotates the nozzles through a predetermined horizontal arc and also raises and lowers the cleaning apparatus. The cleaning apparatus is supported on a mobile derrick for movement of such apparatus along guide rails between a plurality of container tanks. The reactive forces produced by the liquid spray on the spray nozzles are balanced so that the total bending force exerted on the vertical shaft is kept at a minimum regardless of the position of the folding support arms carrying such nozzles.
U.S. Pat. No. 3,827,634 discloses a cleaning device for the interior of tanks, silos and the like which has a foldable and spreadable framework carrying spray heads. The framework can be folded to permit insertion through an opening, and can then be spread in the interior of the receptacle. The interior framework can be rotated about a longitudinal axis, and each of the spray heads can in itself be rotated with reference to the framework.
U.S. Pat. No. 3,791,393 discloses a tank cleaning apparatus for cleaning the interior of elongated tanks or tanks where access to the interior is limited including a tank cleaning machine attached to a source of cleaning liquid. The tank cleaning machine is movably affixed to a track and drives along the track during the cleaning operation, the track extending through the area of the tank to be cleaned so that the cleaning operation extends to portions of tank interior where access from the outside is limited. An externally mounted gas tight winch is preferred as the drive. A flexible hose provides connection between the tank cleaning machine and the source of cleaning liquid and the hose may be calibrated so that the position of the tank cleaning machine within the tank can be determined. Entry to the tank interior for mounting and dismounting the tank cleaning machine on the track is through an entry port located adjacent one end of the track.
U.S. Pat. No. 3,542,593 discloses a method and apparatus for cleaning a bedded residue from the floor of a tank such as a fermentation tank of a brewery. Arms are provided from which pressure jets of water are sprayed and which can be raised and lowered by pressure of the water through regulation of the volume supplied, the arms being foldable into a small compass for passing the same through the tank's manhole. The arms are also provided with scraper vanes attached to the underside of same to facilitate movement of the yeast to the outlet drain of the fermentation tank.
U.S. Pat. No. 3,188,238 discloses a tank cleaning method and apparatus for the cleaning of tanks used for the storage of chemicals and carried on a portable supporting structure, the apparatus including a cleaning fluid container, a device for applying pressure to the fluid in the container, the container also being supported by the structure, a fluid spray head adapted to be inserted into the tank, a conduit communicating the container with the spray head, a source of pressurized gas, and a conduit connecting the spray head with the source whereby the fluid and the gas can be simultaneously introduced into the spray head to form a mist which is distributed throughout the interior of the tank, and wherein pressure is applied to the fluid by a pneumatic device which is included in an air brake system for the structure, the pneumatic device also providing a source for the pressurized gas.
U.S. Pat. No. 3,182,669 discloses a combined a tanker service unit for installation within fluid containing tanks, the service unit including a vertically disposed tubular structure anchored within the tank, the tubular structure having one or more heating sections, and one or more diffusion sections, nozzles in the diffusion sections directed exteriorly of the sections, a device to supply a heating medium condensate from the heating sections, and a device to supply a cleaning fluid to the diffusion sections for ejection through the nozzles.
U.S. Pat. No. 2,074,052 discloses an apparatus for cleaning the interior of tanks including the combination of a laterally flexible member acting both as support and supply pipe and capable of being extended to a variable depth within the tank, and a spray head on the end of the support, the spray head including a fixed body being formed into an external bevel gear, a second portion of the body being formed into a second gear, and with a liquid passage in the interior of the fixed body, and a rotating body rotatively affixed to the fixed body, the rotating body having a cross form, with internal water passages, one arm of the cross terminating in a yoke, carrying a worm gear, the water passage in this arm extending through one side of the yoke and axially through worm gear shaft, which shaft extended, terminates in a T having mounted therein nozzles or reaction type to convert liquid pressure into rotative motion of shaft and worm which is rotatively mounted in the yoke, whereby the worm, working upon the second gear of the fixed body may cause the rotating body to turn with respect to the fixed body about their common center-line, the other arm of the cross having rotatively mounted upon its outer end a bevel gear which meshes with the bevel gear of the fixed body, the water passage of this cross arm extending axially through the bevel gear and terminating in a T having mounted therein nozzles formed to convert liquid pressure into velocity energy of jets.
U.S. Pat. No. 1,545,896 discloses an apparatus for washing sediment from oil tanks, including the combination of a pipe, a discharge nozzle on the end of the pipe, a device within the tank supporting the nozzle for translatory movement in a horizontal plane, and a device operable from the exterior of the tank for moving the nozzle in a vertical plane.